Clutch means for selectively coupling a single input to one or more plural outputs



United States Patent Frank Holper 75 Blufl, Cary, 111. 60013 760,789

Sept. 19, 1968 Dec. 15, 1970 Inventor Appl. No. Filed Patented CLUTCH MEANS FOR SELECTIVELY COUPLING A SINGLE INPUT TO ONE OR MORE PLURAL OUTPUTS 5 Claims, 3 Drawing Figs.

US. Cl 192/48.2, l92/48.91. 192/84: 76/665: 338/1 16 Int. Cl ..Fl6d 21/04, F1 6h 37/06 Field of Search l92/48.2,

48.9. 48.91, 84, 84(A). 84(A l (A2); 74/665(G1).(G5);338/116 [56] References Cited UNITED STATES PATENTS 750,370 1/1904 Kammerer l92/84(A1) 1,243,529 10/1917 Koch 192/84(A)(X) 2,474,663 6/1949 Goddard 74/84(X) 2,487,702 11/1949 Goodwillie etal.. .74/665(G5)(X) 3,073,180 H1963 Lohr 74/665(G1) 3,101,628 8/1963 Shelley etal 74/665(G1) 3,157,259 l1/1964 Bialek 192/84(A) Primary Examiner-Allan D. Herrmann An0rney-Kinzer, Dom and Zickert ABSTRACT: A control system characterized by variantly positionable shafts is so arranged that the shafts may be positioned collectively or individually, and only a single drive motor is required to accomplish this, selective energization of electromagnets being effective to determine which shaft shall be active.

CLUTCH MEANS FOR SELECTIVELY COUPLING A SINGLE INPUT TO ONE OR MORE PLURAL OUTPUTS This invention relates to control systems which may be governed by potentiometers, and in particular to systems of this kind which may be embodied in a television receiver set, although the invention in its basic form has many areas of utility other than this.

There are many instances where a plurality of independent functions are achieved by variantly positionable shafts. An example of this is presented by a television receiver set where tuning and volume settings are attained by either remotely or immediately adjusting the shaft of a potentiometer upon energizing a motor. In the present day construction there is a potentiometer for each function and a motor for each potentiometer, and the'primary object of the present invention is to enable anyone or all functional settings to be realized through a singledrive motor, thereby greatly reducing the unit costs.

While the primary utility of the present invention is thus established in terms of television receiver installations, it will be appreciated that this is but one example of utility. Thus, the primary object of the present invention, as inferred, is to enable a single drive motor to be used to position any one of a plurality of shafts the angular position of which represents a predetermined function. The set position of the shaft itself sets the potentiometer, or the shaft member may'carry a sprocket, which is to say that the position to which the shaft is turned is an analog of the ultimate effect of whatever element or device is responsive to shaft positioning. Therefore, a related and more specific object of the present invention is to deliver to any selected one of a plurality of such shafts, independently of one another, torque derived from a single drive motor and to accomplish this by associating with each shaft anindependent rotary power input element which is free to rotate with respect to the related shaft, and which carries a facing of magnetically attractable material rotatable with the input a element; an electromagnet is fixed to the shaft and the pole pieces of the electromagnet are opposite said facing, but ordinarily spaced therefrom, such that when the electromagnet is energized, the pole pieces and the facing are coupled whereby the torque of the input element is transmitted to the electromagnet and from the electromagnet to the shaft, thereby driving the shaft.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawing which,"by way of illustration, shows preferred embodiments of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodyingthe same or equivalent principles may be made as desired by those skilled in the art without departing from the present invention. In the drawings:

FIG. I is a perspective view, partly in section, of a unit constructed in accordance with the present invention;

FIG. 2 is a plan view, partly schematic, illustrating a system constructed in a accordance with the present invention;

FIG. 3 is a perspective view, partly schematic, suggesting another embodiment of a system constructed in accordance with the present invention.

Referring to FIG. I the control unit there illustrated is one of several identical units which may be incorporated in an entire control system as will be evident from FIG. 2, each such unit including a potentiometer ll, the outpu't function of which is determinedby the angular position of a potentiometer control shaft 12. It will be appreciated that the potentiometer is but a variable resistor, the resistance setting' of which varies the output current delivered through a potentiometer output terminal board! 1T.

The electromagnet 16 is of coil form, as will be described in more detail, and is concentric with and fixed. to the potentiometer shaft 12 so as to be coaxial therewith.- I

The electromagnet 16 comprises a bobbin 17 of insulating material affording a pair of end flanges 17F and a spool or sleeve 18 between and on which the usual wire coil 19 is wound. When the electromagnet coil is energized, a magnetic field is created, and this magnetic field is concentrated by the usual iron core 20 having associated therewith a short front pole piece 22 and a longer rear pole piece 24. It will be appreciated that the core 20 and the pole pieces may be pressfitted to the shaft 12 to fix the electromagnet to the shaft 12.

Each of the pole pieces 22 and 24 is substantially of yoke form as perhaps best shown in FIG. 3, which is to say that each pole piece includes a bight portion 23 and a pairof parallel forwardly projecting arms 25 spaced one from another and extending at right angles to the bight 23. As will be evident in FIG. 3, the pole pieces 22 and 24 are in effect crossed to be displaced 180 relative one to another, when assembled, and together are effective to present four end portions 22E at the free ends of the arms 25 separated by The four pole piece ends displaced 90 one from another as thus presented, are opposed to a low permeability washer 30 present as a facing on a rotary input element 31 in the form of a gear freely mounted on the shaft 12 and disposed between the potentiometer 11 and the electromagnet 16.

While the rotary input element 31 is in the form of a gear, it may be a pulley, but in any event is free to rotate on the shaft 12. Suitable thrust washers or spacers may be interposed between relatively movable parts assembled on shaft 12.

The facing washer 30 is magnetically attractable, and is preferably of soft iron constituency so as to be readily responsive to the magnetic field created adjacent thereto by the pole piece ends when the electromagnet is energized. The washer 30 may be secured for rotation to the input element 31 in many different ways, but I prefer that such mounting be by way of a pair of pins 33, FIG. 1, fixed to and projecting from the face of gear 31, the pins 33 allowing the washer 30 to partake of a slight amount of axial motion in the direction of the electromagnet 16 when the latter is energized to create a magnetic field.

Ordinarily, with the electromagnet unene'rgized, any rotary motion imparted to the gear 31 is simply manifest in the latter idling on the shaft 12, carrying the washer 30 along by means ofthe pins 33; but when the electromagnet 16 is energized, the pole pieces 22 and 24 are magnetized and the washer 30 is attracted to the pole piece ends 22E whereby the input gear 31 is in effect coupled to the potentiometer causing the latter to rotate with the gear 31. In this connection, it is important to observe that the four pole piece ends will. couple at four different areas to the outer periphery or margin of the washer 30.

By virtue'of this arrangement, a high degree of efficiency is realized in transmitting torque from the gear 31 to the electromagnet 16, and resultantly the electromagnet turns the shaft 12 of the potentiometer to set or vary the function of the potentiometer. Also, in FIG. 3, note how the four pole piece ends in effect produce four interlocked magnetic fields (N-S- N-S) between the gear facing and electromagnet.

The primary advantage of the unit thus disclosed in FIG. 1 will be evident from FIG. 2 where there is'disclosed a typical system comprising three potentiometers 11A, 11B and 11C. Each potentiometer, FIG. 2, represents a different television receiver function.

In the system presented in FIG. 2 all drive motors in the conventional television receiver set formerly associated with the three potentiometers may be eliminated, while utilizing a single motor M as a source of torque for positioning any one of the three potentiometer shafts.

In any event, the input gear 31 associated with electromagnet 16A is driven by a gear 40 in turn driven by motor M. The coupled gears 31, FIG. 2, may have idler gears 35 associated therewith to establish a common direction of rotation for all shafts 12 if necessary. It will be realized thatthe manner in which the parts are supported to establish the arrangement as shown in FIG. 2 constitutes no part of the present invention, and hence is not illustrated.

In the event that pulleys replace the gears, FIG. 2, then of course belts become the transmitting means.

When the drive pinion 40 is driven, all gears are constantly rotated, and when it is desired to impart a functional setting to a potentiometer on a shaft 12, then its electromagnet 16A,

168, or 16C, as the case may be, is energized by closure of an appropriate switch to complete a circuit to the conductors 15, FIG. 1, resulting in coupling of the input element to the thus eit ergized electromagnet. The'electromagnets, FIG. 2, may be i'iergi'zed independently or all at once, andas will be appreciated. upon comparing FIG. 3 to FIG. 2, the gears (or pulle ys) may be in a tandem arrangement or in a cluster, noting that only the pole pieces of a single electromagnet are shown in' FIG. 3.

.The manner in which a shaft 12 is stopped in its set position plays no part in. the present invention, and hence is not illustrated. Thus, the potentiometers may have internal stops, and the pulleys when used may have physical stops, the torque of the motor M being weak enough at partial voltage to prevent .afy physical abuse. n the other hand, the electromagnets rn'ay themselves be controlled by automatic switches or timers solthat the angle through which the shaft 12 is turned is itself a function of the time period of holding energized the related electromagnet.

yPotentiometers such as these will not be rotated through an angle of more than 360. The electrical leads (not shown) may therefore be flexible and conventional, and in an extreme case rings may be used for supplying current to the coils.

lt will be seen from the foregoing under the present invention, shafts that are variantly setable to or through a predetermined angle may be collectively or individually moved to set position by torque derived from a single drive motor. This is made possibly possible by a train of gears,,pulleys or other rotary input elements, each one on a related shaft for independent movement relativeto the shaft, and when it-is desired to turn the shaft, an electromagnet fixed thereto is energized to couple its pole piece to the rotary input element. Of significance to television receiver sets is the fact that hand setting (external knobs) is by no means rendered any m'ore difficult in the:pre'sent instance. v 1

E-l-lence, while I have illustrated and described the preferred embodiments of my invention, it is to be understood that we aricapable of variation and modification withinthe purview of the following claims:

lclaim:

1. In a control system comprising a plurality of variantly positionable shafts the angular setting of which represents a predetermined function, a rotary power input element freely mounted on each shaft for independent rotation with respect to the related shaft, the input elements being coupled so that rotation of one is imparted to another, each of said elements presenting a facing of a magnetically attractable material rotatable therewith, an electromagnet mounted concentrically about and fixed to each shaft, means for energizing the electromagnets independently of one another,-and a pole piece fixed to each electromagnet in a position'opposed to the related one of the facings and effective upon energization of the related electromagnet to couple to the related .facing thereby enabling controllable torque to be transmitted to the related shaft.

2. A control system according to claim 1 in which each electromagnet is in the form of a coil with its axis coaxial with the related shaft, each of said electromagnets having pole pieces at opposite ends of the coil and each pole piece being of yoke form displaced approximately 180 so that there are four pole piece ends about apart opposite each of said facings.

3. A control system according to claim '2in which each shaft controls a potentiometer in a television receiver set.

4. A control system according to claim 3 in which the system includes only a single drive motor 'which imparts torque to one of the input elements.

5. in a control system comprising a positionable shaft the angular setting of which represents a predetermined function, a rotary power input element freely mounted on the shaft for independent rotation with respect to the related shaft, said input element presenting a facing of a magnetically attractable I material rotatable therewith, an electromagnet mounted con- 

